The instant invention describes an improved marine vehicle or ship that has substantial efficiency advantages compared to other marine vehicles. In its preferred embodiment, it offers the high efficiencies of marine vehicles that are partially supported by blower fan supplied pressurized gas cushion(s) that are disposed between the marine vehicle and the water surface. Examples of gas cushioned craft are the hovercraft or Surface Effect Ship (SES). Examples of such a gas-cushioned craft are given in applicant""s U.S. Pat. Nos. 5,611,294 and 5,626,669.
The improved marine vehicle also has means to create a great enhancement of its aerodynamic lift by increasing lift over a preferably at least partially airfoil shaped upper surface of the improved marine vehicle. This is enhanced by drawing air into a portion of said upper surface to in effect create a boundary layer control system. It is offered that the preferred source of power for the boundary layer control system is air used to supply the inlet air to the blower supplying gas to the gas cushion(s). Optional sources of power for the boundary layer control system include air directed to the propulsion system engine(s) and/or air to the propulsor itself. It is also possible to use a flow deflector to direct and accelerate airflow over the upper surface of the vehicle.
There are vehicles that have a wing that operates close to the water or ground surface thereby increasing their lifting efficiency at cruise speeds by compressing the air under the wing to create a water or ground effect. These are sometimes called Wingships. Some of applicant""s patents that describe versions of Wingships are U.S. Pat. Nos. 5,611,294 and 5,626,669. The Wingship can actually transition from a waterborne to an airborne mode of operation. Wingships normally have relatively thin wings like aircraft for low drag coefficients when airborne. Ideally speaking however, a wing with the highest coefficient of lift would have a large radius leading edge and a very thick shape. It would also have a high camber in its most desired embodiment. Its shape requires that the air passing over the upper surface of the wing travel significantly further and hence faster than the air traveling over the upper surface of a thinner wing as used on aircraft. By Bernoulli""s equations this results in a lower static head or pressure on the top of the instant invention""s thick section wing and hence a much higher coefficient of lift compared to a thin section aircraft style wing. However, in the process of doing this there is, as speed increases, a separation of airflow from the top of the thick section wing. The main body of the instant invention uses a thick section wing but applies means to overcome the flow separation problem. It does this by means of: 1) Boundary layer bleeds, 2) Flow augmentation means, and/or 3) Flow directing vanes. As a result, it offers coefficients of lift that are about twice that of state of the art thin section wings used on aircraft. The instant invention""s thick section wings still realize the significant benefits of ground effect lift on their undersides as they operate close to the water surface. There have been studies of thick section wings that use boundary layer bleeds or flow augmenting means with published results showing better than a two times lift coefficient improvement compared to thin section wings. A discussion of the performance of such a thick section wing is given on pages 232 and 233 of xe2x80x9cTheory of Wing Sectionsxe2x80x9d by Ira H. Abbott and Albert E. Van Doenhoff as published by Dover Publications, Inc., New York, N.Y., copyright 1959, Library of Congress No: 60-1601. There appears to have been no practical application to today""s higher speed aircraft since the frontal profile area of the thick section wings created excessive drag at high speeds plus, importantly, it was deemed too expensive and weighty to incorporate and drive the necessary blower fans to either bleed off and redirect the boundary layer or supplement it with large volumes of gas flow. Applicant addresses these problems by: 1) Operating at relatively low marine vehicle speeds and 2) Utilizing the tremendous volumes of air flow required by the large blower fans that supply the pressurized gas cushions of the SES or hovercraft and/or the air required by gas turbines used for propulsion power and/or air directed to the inlets of propulsors to bleed off gas flowing over the upper surfaces of a thick section wing.
The instant invention offers further means to improve performance that offer much advantage. A few of these improvements include: 1) A transversely oriented curvilinear upper surface shape to the gas cushion recess(es) in the hull(s) that acts to add considerable structural strength to the hull as well as to reduce displacement when the blowers are off, 2) A novel aft seal for the recess that reduces leakage from the gas cushion, 3) Water friction reducing steps set into the sides of the hull(s) that are unique in that they are inset behind a chine which improves performance when the marine vehicle is getting onto plane as well as when operating at speed in rough seas, 4) Optional, preferably retractable, sidewings that, while lightweight in construction, offer considerable aerodynamic efficiency advantages, and 5) The ability to transition to wing in ground effect flight at least mostly free of the water when an air propulsor rather than a water propulsor is installed.
There are further improvements over the previous art that will become apparent upon examination of the remainder of this application.
The primary object of the instant invention is to provide a superior high efficiency marine vehicle that includes a boat hull where said boat hull has means to restrain an artificially pressurized gas cushion between the boat hull and a water surface.
It is a directly related object of the invention that a means to artificially pressurize the gas cushion can take the form of a powered blower fan, engine exhaust, or other gas pressurizing means.
It is another object of the invention that said artificially pressurized gas cushion is at least in part restrained by a recess built into an underside of the boat hull.
It is an object of the invention that one or more of its multiple hulls can include the air cushion recess(es) that are pressurized with gas and that one or more of its multiple hulls do not have the gas cushion recess(es).
It is a related object of the invention that said gas cushion recess, in its optimum configuration, converges going forward over at least a portion of its length.
It is another related object of the invention that the gas cushion recess is bordered, at least partially, by recess sidekeels where at least one of said sidekeels converges toward the other over at least a portion of its length going from aft to forward.
It is a directly related object of the invention that a distance from where said sidekeels begin converging going forward to a forward portion of the boat hull that is in water contact, as seem in a calm sea surface waterline when the recess(es) are not pressurized with gas, extends over at least twenty-five percent of a waterline length of said boat hull.
It a further directly related object of the invention that from where said sidekeels begin converging going forward to a forward portion of the boat hull that is in water contact there is formed an included angle of less than twenty-six degrees.
It is yet another object of the invention that gas cushion recess(es) can have curvilinear upper surfaces as seen in a transverse plane of the hull to greatly add strength to the hull and to reduce draft when the gas cushion is not pressurized.
It is a further object of the invention that a transversely oriented gas cushion recess seal can include a step seal.
It is a directly related object of the invention that the step seal can be vented or pressurized to thereby aid in its sealing effectiveness.
It is still another object of the invention that water-deflecting steps can be inset into sides of the hull(s).
It is a directly related object of the invention that the water deflecting steps can be inset above a chine of the hull(s) to thereby reduce or eliminate their water contact when the marine vehicle is coming on plane while also reducing water contact in rough seas when the vehicle is operating at high speeds.
It is a further object of the invention that it can utilize aerodynamic lift to augment its performance.
It is a related object of the invention that at least a portion of the aerodynamic lift is obtained from air flowing over an upper surface of the marine vehicle and thereby creating a reduced static pressure on said upper surface.
It is another object of the invention that aerodynamic lift is, at least in part, generated by air flowing over a structure that is at least partially in the form of a thick section wing.
It is an object of the invention that the thick section wing, also referred to as the first wing or main wing, be in mechanical communication with the boat hull.
It is another object of the invention that there be a means to bleed off gas flowing over upper surfaces of the first wing as a form of boundary layer control.
It is a directly related object of the invention that the means to bleed off gas flowing over upper surfaces of the first wing can include devices such as blower fan(s) or engine(s) where the engine(s) is using the bleed off gas for at least part of its required gas inlet flow.
It is a further object of the invention that gas can be supplied to an upper surface of the first wing by means of powered blower fan(s), engine exhaust, or other gas pressurizing means.
It is a related object of the invention that a propulsion system engine can bleed off part of the gas flowing over the upper surfaces of the first wing for use as engine inlet gas and supply its exhaust gas to an upper surface of the first wing.
It is yet another object of the invention that an air propulsor can be utilized to provide propulsive thrust.
It is a directly related object of the invention that such an air propulsor can take its inlet air from upper surfaces of the first or main wing.
It is yet another object of the invention that a second wing can be disposed, at least in its majority, above the first wing with said second wing used to aid in flow control over the first wing.
It is another object of the invention that the first wing can have sideplates proximal either end of its span.
It is a further object of the invention that the first wing can include a fore to aft oriented bisecting structural member.
It is yet another object of the invention that a majority of payload of the inventive marine vehicle can be carried internal to the first or main wing.
It is another object of the invention that it can include port and starboard sidewings where such sidewings can provide ground effect lift when the vehicle is moving forward.
It is a directly related object of the invention that the sidewings can include winglets proximal their outer ends.
It is another related object of the invention that the sidewings are retractable.
It is a further object of the invention that the subject marine vehicle be capable of transition to airborne flight.
It is yet another object of the invention that a moveable, in relation to the instant invention marine vehicle, seal be disposed on the underside of the main wing.
It is a directly related object of the invention that the movable seal be flexible in nature.
It is a further directly related object of the invention that the movable seal can be inflated with pressurized gas.
The invention will be better understood upon reference to the drawings and the detailed description of the invention which follow in which: